O, o-di-lower alkyl-s-[(p-lower alkylmer-capto-phenyl)-lower alkoxycarbonyl-methyl]-dithiophosphates



United States Patent 3,377,410 0,0-DI-LOWER ALKYL-S-[(p-LOWER ALKYLMER- CAPTO-PHENYL)-LOWER ALKOXYCARBONYL- METHYL1-DITHIOPHOSPHATES Richard Sehring and Karl Zeile, Ingelheim am Rhine,

Germany, assignors to C. H. Boehringer Sohn Iugelheim am Rhine, Germany, a limited partnership of Germany No Drawing. Continuation of application Ser. No. 333,207, Dec. 24, 1963. This application Aug. 3, 1967, Ser. No. 658,294 Claims priority, application Germany, Jan. 4, 1963, B 70,221; Oct. 25, 1963, B 74,017, B 74,018 4 Claims. (Cl. 260-941) This application is a continuation of S.N. 333,207, filed Dec. 24, 1963, now abandoned.

This invention relates to novel 0,0-dialkyl-dithiophosphoric acid esters, as well as to pesticidal compositions comprising said novel compounds as active ingredients and to a pesticidal method.

More particularly, the present invention relates to novel 0,0-di-lower alkyl-dithiophosphoric acid esters of the formula selected from the group consisting of where A is alkyl of 1 to 4 carbon atoms, R is selected from the group consisting of hydrogen,

alkyl of 1 to 3 carbon atoms and CH X-R where X is selected from the group consisting of oxygen and sulfur, and R is alkyl of 1 to 3 carbon atoms,

R, is selected from the group consisting of hydrogen and alkyl of 1 to 3 carbon atoms,

and

n is an integer from to l, inclusive.

The novel 0,0-di-lower alkyl-dithiophosphoric acid esters embraced by the Formulae Ia-Ic above may be prepared by various methods which involve well known chemical principles. Most conveniently, however, they are prepared by reacting a salt, preferably an alkali metal salt, of an 0,0-di-lower alkyl-phosphoric acid with a 3 ,377,410 Patented Apr. 9, 1968 compound of the formula selected from the group consisting of wherein Hal is a halogen, preferably chlorine or bromine, and R R R R R and n have the meanings defined above. v

The following examples will further illustrate the prescut invention and enable others to understand it more completely. It should be understood, however, that the present invention is not limited to the particular examples given below. I I

EXAMPLE 1 Preparation of QO-dimethyl-S-(3-ethoxymethyl-4- methyhnercaptobenzyl)-dithiophosphate 13.5 gm. of sodium 0,0-dimethyl-dithiophosphate were dissolved in' 50 cc. of methyl isobutyl ketone, and the resulting solution was admixed dropwise with 14 gm. of 3-ethoxymethyl-4-methylmercapto-benzyl chloride at 60- 70 C., accompanied by stirring. The reaction mixture was then stirred at 70-75 C. for about four hours, whereupon the reaction had gone to completion. The sodium chloride which had separated out during the reaction was separated by vacuum filtration, the filtrate was evaporated in vacuo, and the residue was taken up in 50 cc. of ether. The ethereal solution was then washed by shaking with 50 cc. of water, dried and evaporated 40 in vacuo. The residue was then freed from residual volatile components by heating it on a boiling water bath at-a pressure of 0.2 mm. Hg, 17 gm. of a non-distillable oil remained behind, which was identifiedto be 0,0- dimethyl S (3 ethoxymethyl 4 methylmercaptobenzyl)-dithiophosphate of the formula CHaO s The yield was 80% of theory. i

Analysis.Phosphorus--calculated, 8.82%; found, 8.70%. Sulfur-calculated, 27.3%; found, 27.15%.

I EXAMPLE 2 Preparation of QO-diniethyl S [(4 methylmercaptobenzyl)-mercaptoethyl] -dithiophosphate 20 gm. of sodium 0,0-dimethyl-dithiophosphate were dissolved in cc. of methyl isobutyl ketone, and the resulting solution was admixed dropwise at 60-70 C. with 23 gm. of 4-methylinercapt'o-benzyl -6 chlorethylthioether. The reaction mixture was then stirred for about four hours at C., whereupon the reaction had gone to completion. The sodium chloride which had precipitated during the reaction was separated by vacuum filtration, the filtrate was evaporated in vacuo, and the residue was taken up-in-50 cc. of benzene. The benzene solution was then washed by shaking it with 50 cc. of water, dried, and the benzene was distilled off in vacuo. 28 gm. of a nondistillable oil remained behind, which was identified to be 0,0-dimethyl-S-[(4-methylmercapto benzyl mercaptoethyl3-dithiophosphate of the formula CHaO S The yield was 79.0% of theory.

Analysis.Phosphoruscalculated, 8.76%; found, 8.54%. Sulphur--calculated, 36.1%; found, 36.0%.

EXAMPLE 3 Preparation of 0,0 diethyl S [(p methylmercaptophenyl) -ethoXycarbonyl-methyl] -dithiophosphate 13. gm. of sodium 0,0diethyl-dithiophosphate were dissolved in 40 cc. of methylisobutyl kctone, and the resulting solution was slowly admixed with 10 gm. of (p-methylmercapto phenyl) ethoxycarbonyl methyl chloride at 60 C., accompanied by stirring. The reaction 16.3 gm. of a non-distillable oil remained behind, which N was identified to be 0,0-diethy1-S-[(p-methylmercaptophenyl) ethoxycarbonyl methyl] dithiophosphate of the formula CzH5O S-CH S-CH3 The yield was 100% of theory.

Analysis.Phosphorus--calculated, 7.87%; found,

7.75%. Sulfurcalculated, 24.35%; found, 24.30%.

EXAMPLE 4 4 EXAMPLE 6 Using a procedure analogous to that described in Example 3, 0,0-dimethyl-S-[( pmethylmercapto phenyl)- ethoxycarbonyl-methyl]-dithiophosphate of the formula CH30\ S C aO was prepared from sodium 0,0-dimethyl-dithiophosphate and (-p-rnethylmercapto-phenyl)-ethoxycarbonyl methyl chloride.

The product was a non-distillable oil.

Analysis.Phosphoruscalculated, 8.47%; found,

8.32%. Sulfur-calculated, 26.22%; found, 26.37%.

EXAMPLE 7 Using a procedure analogous to that described in Example 3, 0,0-dimethyl-S -[(p-methylmercapto-pheuyl)- isopropoxycarbonybmethyl]-dithiophosphate of the formula CHsO S from sodium 0,0 dimethyl dithiophosphate and (pmethylmercapto phenyl) isopropoxycarbonyl methyl chloride.

Using a procedure analogous to that described in Example 1, 0,0-dimethyl- (p-methylmercapto phenyl)- methylmercapto-methyl]-dithiophosphate of the formula omo s S z was prepared from sodium 0,0-dimethyl-dithiophosphate and (p-methylmercapto-phenyl)-rnethylrnercapto methyl chloride. The product was a non-distillable oil.

Analysis.Phosphorus--calculated, 9.12% found, 9.07%. Sulfurcalculated, 37.05%; found, 37.10%.

EXAMPLE 5 The product was a non-distillable oil. Analysis.Phosphoruscalculated, 8.15%; found, 8.10%. Sulfur-calculated, 25.24%; found, 25.30%

EXAMPLE 8 Using a procedure analogous to that described in Example 1, 0,0-diethyl-S-[1-(p-methyl-mercapto-phenyl) ethyl-1]-dithiophosphate of the formula was prepared from sodium 0,0-diethyl-dithiophosphate and 1-(p-methylrnercapto-phenyl)-ethyl1 chloride. The

product was a non-distillable oil.

Analysis.Phosphoruscalculated,

9.23%; found,

9.10%. Sulfur-calculated, 28.58%; found, 28.65%.

Using a procedure analogous to that described in EX- ample 1, 0,0-dimethyl-S-[ (p methyl-mercapto phenyl)- ethoxy-methyl]-dithioph0sphate of the formula CBaO S was prepared from sodium 0,0-dimethyl-dith iophosphate and (p-methylrnercapto-phenyl)-ethoxy-methyl chloride.

The product was a non-distillable oil.

Analysis.-Phosphoruscalculated, 9.17%; found, 9.20%. Sulfur-calculated, 28.18%; found, 28.25%.

(EH50 S-CH;

EXAMPLE 9 Using a procedure analogous to that described in Example 1, 0,0-dimethyl-S-[(p-methylmercapto-phenyl)- ethylmercapto-methyl]-dithiophosphate of the formula i Cal-I GHsO was prepared from sodium 0,0-dimethyl-dithiophosphate and (p methyl-mercapto phenyl)-ethylmercapto-methyl chloride. The product was a non-distillable oil.

Analysis.Phosphorus-calculated, 8.75%; found, 8.60%. Sulfurcalculated, 36.20%; found, 36.35%.

was prepared from sodium 0,0-diethyl-dithiophosphate and 4-methylmercapto-benzyl-fi-chloroethylthio ether. The product was a non-distillable oil.

Analysis.Phosphoruscalculated, 8.12%; found, 8.01%. Sulfurcalculated, 33.55%; found, 33.40%.

EXAMPLE 11 Using a procedure analogous to that described in Example 2, 0,0-dimethylS-[(3-methyl-4-rnethylmercaptobenzyl)-mercaptoethyl]-dithiophosphate of the formula CHaO S was prepared from sodium 0,0-dimethyl-dithiophosphate and (3-methyl-4-methylrnercapto-benzyl)- 8-chloroethylthio ether. The product was a non-distillable oil.

Analysis.Phosphoruscalculated, 8.43%; found, 8.29%. Sulfurcalculated, 34.80%; found, 34.70%.

EXAMPLE 12 Using a procedure analogous to that described in EX- ample 2, 0,0-dimethyl S [p-ethylmercapto-benzyl)- mercaptoethyl]-dithiophosphate of the formula was prepared from sodium 0,0-dimethyl-dithiophosphate and (p-ethylmercapto-benzyl) B chloroethylthio ether. Theproduct was a non-distillable oil.

Analysis.Phosphoruscalculated, 8.43%; found, 8.30%. Sulfurcalculated, 34.80%; found, 34.90%.

EXAMPLE 13 Using a procedure analogous to that described in Ex ample 3, 0,0-dimethyl-S[(prnethylmercapto-phenyl)- ethoxycarbonyl methylmercapto ethyl]-dithiop'hosphate of the formula CzHaO CHsO was prepared from sodium 0,0-dimethyl-dithiophosphate and V (pmethylmercapto-phenyl)-ethoxycarbonyl-methylfl-chloroethylthio ether. The product was a non-distillable oil.

Analysis.Phosphoruscalcu1ated, 7.28%; found, 7.29%. Sulfurcalculated, 30.00%; found, 29.90%.

EXAMPLE 14 Using a procedure analogous to that described in Example 1, 0,0-diethyl-S-(3-ethoxymethyl-4-methylmercapto-benzyl)-dithiophosphate of the formula P f 0211 0 S-CHz- S-C a 6 was prepared from sodium 0,0-diethyl-dithiophosphate and 3-ethoxymethyl-4-methylmercapto-benzyl chloride. The product was a non-distillable oil.

Analysis.-Phosphoruscalculated, 8.16% found, 8.09%. Sulfurcalculated, 25.22%; found, 25.35%

EXAMPLE 15 Using a procedure analogous to that described in Example 1, 0,0-diethyl-S-(3-methoxyrnet-hyl 4-ethylmercapto-benzyl)-dithiophosphate of the formula I CH -O CH3 was prepared from sodium 0,0-diethyl-dithiophosphate and 3-methoxymethyl 4-ethylmercapto-benzyl chloride. The product was a non-distillable oil.

Analysis.- Phosphoruscalculated, 8.16%; found, 8.03%. Sulfurcalculated, 25.22%; found, 25.40%.

EXAMPLE 16 'Using a procedure analogous to that described in EX- ample 1, O,'O-diethyl-S-(3-isopropoxymethyl 4-methylmercapto-benzyl)-dithiophopshate of the formula CzH50 was prepared from sodium 0,0-diethyl-dithiophosphate and 3-isop-ropoxymethyl 4-methylmercapto-benzyl chloride. The product was a non-distillable oil.

Analysis.Phosphoruscalculated 7.86%; found 7.75%. Sulfurcalculated, 24.39%; found, 24.50%.

EXAMPLE 17 Using a procedure analogous to that described in EX- ample l, O,-O-diethyl S-(3 methylmer'captomethyl -.4-

methylmercapto-benzyl)-dithioph0sphate of the formula was prepared from sodium 0,0-diethyl-dithiophosphate and 3-methylmercaptomethyl 4-methylmercapto-benzyl chloride. The product was a non-distillable oil Analysis.--Phosphoruscalculated, 8.12% 8.0.% Sulfurcalculated, 33.52%; found, 33.75%.

EXAMPLE 18 -Using a procedure analogous to that described in Example 3, 0,0-diethyl-S-['(3-ethoxymethyl 4-methylmercapto-phenyl -ethoXycarbony1-methyl] -dithioph0sphate of the formula found,

Cal-I50 S 021150 SCH S-CHa l CHr-0-C2H5 OCzH was prepared from sodium 0,0-diethyl-dithiophosphate and (3-ethoxymethy1 4 methylmercapto-phenyl)-ethoxycarbonyl-methyl chloride. The product was a nondistillable oil.

Analysis.Phosphoruscalculated, 6.85

found, 6.67%. Sulfurcalculated, 21.22%; found 21.35%

7 EXAMPLE 19 CHaO S was prepared from sodium 0,0-dirnetl1ylditl1ioph0sphate and (3-ethoxymethyl-4-methylmercapto-benzyl)-;3-chloroethylthio ether. The product was a non-distillable oil.

Analysis.Phosphorus-calculated, 7.53%; found, 7.41%. Sulfur--calculated, 31.00; found, 31.10%.

The novel compounds according to the present invention, that is, those embraced by the Formulae Ia-Ic above, are highly effective broad-spectrum pesticides; they act not only as contact poisons but also as alimentary canal poisons. Their toxicity toward warm-blooded animals is extremely low.

The novel 0,0-dialkyl-dithiophosphate are particularly effective against red spider mites, aphids, weevils (Calandra), bedbugs (Cimex lectularz'us), roaches and the common housefly.

For pesticidal purposes the compounds according to the present invention are disseminated in the form of compositions consisting esentially of an inert carrier and a pesticidally effective amount of the active ingredient. The inert carrier may be a gaseous substance, such .as a propellant gas, or a liquid or solid substance. In addition, the compositions may comprise one or more other inert additives, such as emulsifiers, extenders and substances which increase the adherence of the compositions to surfaces or objects to which they may be applied. The compounds of the present invention may be the sole active pesticidal ingredients in the compositions, or they may be combined with other pesticidal agents. Examples of suitable forms of such compositions are, among others: dusting powders, suspensions, emulsions, solutions, aero sols, fumigating paper or powder, and ointments.

The preferred concentration of the compounds according to the present invention in such pesticidal compositions is from 0.01 to 5% by weight.

The following examples illustrate various types of pesticidal composition comprising a compound of the present invention as the active ingredient.

EXAMPLE 20 Emulsion 40 gm. of 0,0-diethyl-S-i(p-methylmercaptophenyl)- ethoxycarbonyl-met-hyl]-dithiophosph-ate, 20 gm. of xy-' lene and 40 gm. of naphthalene sulfonate were emulsified in an amount of water sufiicient to make the concentration of the dithiophosphate from 0.01 to 0.2% by weight, based on the overall weight of the emulsion.

This pesticidal emulsion is highly efiective against red spider mites, weevils, bedbugs and roaches.

EXAMPLE 21 Suspension The pesticidal suspension was also highly effective against red spider mites, weevils, bedbugs and roaches.

EXAMPLE 22 Dusting powder 2 gm. of 0,0-diethyl-S-[(p-methylmercapto-phenyl)- ethoxycarbonyl-methyl]-dithiophosphate and 98 gm. of kaolin were admixed and milled until a homogenous powder was obtained.

The dusting powder, comprising 2% of the pesticidal ingredient, Was also very effective in combating red spider mites, weevils, bedbugs and roaches.

EXAMPLE 23 Aerosol 5 parts by weight of 0,0-diethyl-S-E (p-methylmercapto phenyl) ethoxycarbonyl methyl] dithiophosphate were dissolved in parts by weight of a difluorodichloromethane, and the solution was filled into aerosol cans at reduced temperature or under pressure.

The aerosol spray thus obtained, comprising 5% by weight of the dithiophosphate, was highly effective against red spider mites, weevils, bedbugs, and roaches.

As pointed out above, the compositions described in Examples 20 to 23 are merely illustrative. It should be understood that the particular dithiophosphate in those illustrative examples may be replaced by any of the other dithiophosphates embraced by the Formulae Ia-Ic above. Similarly, the concentration of the dithiophosphate component may be varied within the limits previously indicated, depending upon the requirements and condi tions. Finally, the inert components of the illustrative compositions may be replaced by equivalent inert materials customarily used in the preparation of pesticidal emulsions, solutions, suspensions, dusting powders, aerosols and the like.

While the present invention has been illustrated with the of certain specific embodiments thereof, it will be readily apparent to others skilled in the art that the in vention is not limited to these particular embodiments and that various changes and modifications may be made without departing from the spirit of the invention or the scope of the appended claims.

We claim:

1. A compound of the formula 1210 S-(l3H- -SRa GOOA wherein R R and R are each alkyl of 1 to 3 carbon atoms,

and r A is alkyl of 1 to 4 carbon atoms. 2. A compound according to claim 1, wherein R R and R are methyl, and A is ethyl.

3. A compound according to claim 1, wherein R R and A are ethyl, and R is methyl.

4. A compound according to claim 1, wherein R R and R are methyl, and A is isopropyl.

References Cited UNITED STATES PATENTS 3,076,009 1/1963 Schrader et a1. 260941 CHARLES B. PARKER, Primary Examiner.

A. H. SUTTO, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,377 ,410 April 9 1968 Richard Sehring et al It is hereby certified that error appears in the above numbered pat ent requiring correction and that the said Letters Patent should read as corrected below.

Column 2 formula IIfa) should appear as shown below:

rial-fcn -cn -a -nizu 4 Column 5, line 64, "found, 7.29% should read found, 7,20% Column 8', lines 47 to 50, the formula should appear as shown Signed and sealed this -'12th day of August 1969 below:

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR

EDWARD M.FLETCHER,JR. Attesting Officer Commissioner of Patents 

1. A COMPOUND OF THE FORMULA 